Specialized stent means fewer heart surgeries for babies

Babies born with a narrowed blood vessel now have a device specifically designed for them, thanks to research conducted at the Smidt Heart Institute and Guerin Children’s at Cedars-Sinai.

The U.S. Food and Drug Administration recently approved the new stent, a metal mesh tube that keeps blood vessels open, for use in newborns, infants and children who have narrowing in the aorta or pulmonary artery. Because the stent expands, it is meant to save these children from additional surgeries as they age and need a larger stent for their growing bodies.

The results of the study are published in Catheterization and Cardiovascular Interventions.

“This approval represents a monumental shift in the way we care for babies with congenital heart disease,” said Evan Zahn, MD, who helped develop the new stent and is director of the Pediatric Congenital Heart Program at Guerin Children’s and in the Department of Cardiology at the Smidt Heart Institute.

“It is a joy to know how many patients and families will be positively impacted now that the stent is more widely available.”

Cedars-Sinai is one of the few hospitals in the U.S. where interventional cardiologists are trained in deploying the stent and where children who need it can get that specialized care.

About 40,000 babies are born with a heart defect every year in the United States, according to the U.S. Centers for Disease Control and Prevention. Many of these children have narrowing in the aorta, the artery that carries blood from the heart to the rest of the body, or in the pulmonary artery, which carries blood from the heart to the lungs.

The FDA approved the first-ever stent in 1994, but for adults. Since then, the only option for babies with narrowing has been to resize an adult stent to fit their tiny vessels and replace the stent multiple times as their bodies grow.

“The stents we have had up to this point have had a fixed maximum diameter, meaning that baby is going to need to get it replaced, typically through open-heart surgery,” Zahn said.

To place the stent, an interventional cardiologist makes a tiny hole in the child’s leg and feeds a long, thin tube called a catheter through the groin and into the narrowed blood vessel. A balloon at the end of the catheter expands the vessel and allows the cardiologist to place the stent.

Over the past five years, Zahn collaborated with engineers at a company called Renata Medical to develop and study the new stent, known as the Minima Stent System. It is made with a unique cell design that allows it to expand to fit a child’s growing body. The expansion is done during a two-hour catheterization procedure rather than through open-heart surgery. Children are expected to be well enough to go home the day after the procedure.

Cedars-Sinai was one of four medical centers involved in an early feasibility study that contributed to the approval of the new stent. The results of that study, published in May, report that the stent was safely implanted and opened narrowed blood vessels.

“This is the start of a game changer for scores of children all around the world,” said Eduardo Marbán, MD, Ph.D., executive director of the Smidt Heart Institute and the Mark S. Siegel Family Foundation Distinguished Chair. “It’s a privilege knowing Cedars-Sinai has been intimately involved in the creation of this device.”